肝动脉供血原发性肝癌320排CT血管成像的低剂量研究

Low-dose 320-slice CT angiography of primary liver cancer

目的探讨320排CT低剂量血管成像在肝癌供血动脉评价中的辐射剂量及对图像质量的影响。方法将87例拟行介入治疗的肝癌患者随机分为两组,术前均以动态容积模式进行320排CT动态增强间隔时间扫描,其中研究组43例的扫描参数采用管电压100 kV,管电流75 mA,对比剂流率5 ml/s,总量50 ml,而对照组40例采用管电压120 kV,管电流100 mA,对比剂速率6 ml/s,总量70 ml;选取最佳纯肝动脉期图像进行三维重建,利用4 D-DSA成像软件测量并比较两组间的肝动脉的强化峰时间和CT值;以DSA为参照,评估两组间肝癌3、4级肝动脉供血支图像质量的优良率和可诊断率,同时比较两组间的辐射剂量。结果研究组的肝动脉达峰值和达峰绝对值均低于对照组(P<0.05),而肝动脉达峰时间和肝动脉平扫CT值与对照组比较均无明显差异(P>0.05);研究组对3、4级肝动脉图像质量评价的可诊断率为97.1%、优良率89.3%,与对照组比较均无明显差异(P>0.05);研究组的有效辐射剂量为(15.07±2.58)m Sv,明显低于对照组(P<0.05)。结论 320排CT低剂量的三维肝动脉成像,不仅图像质量能达到诊断和评价肝癌供血动脉的要求,而且能明显降低患者的辐射剂量。

Objective To investigate the radiation dosage and image quality of low-dose 320-slice CT angiography in evaluating arterial supply of primary liver cancer.Methods 87 patients undergoing interventional therapy of liver cancer were randomly divided to low-dose（43） and control（40） groups.All patients underwent preoperative contrast-enhanced 320-slice CT angiography.The parameters were 100 kV tube voltage,75 mA tube current,and 50 m L contrast medium injection at 5 ml/s for low-dose CT;120 k V,100 m A,70 ml contrast injection at 6 mL/s for control group.The best images in the hepatic arterial phase were selected for 3D reconstruction.The peak CT values and time to peak of the hepatic arteries were determined using 4 D-DSA imaging software.Compared to digital subtraction angiography,the image quality and diagnostic rate of 3 rd and 4 th order branches of the hepatic arteries and the radiation dose were analyzed.Results The hepatic artery peak and absolute peak CT values of low-dose CT were significantly lower than that of the control（P〈0.05）.There was no significant difference in the time to peak and unenhanced CT values of the hepatic arteries（P〉0.05）.The diagnostic rate（97.1%） and rate of good image quality（89.3%） were not significantly different（P〉0.05） from that of the control.The effective radiation dose of low-dose CT（15.07±2.58） was significantly（P〈0.05） lower than that of control group.Conclusion Low-dose 320-slice CT angiography demonstrates well the arterial supply of liver cancer with significant reduction of radiation dose to the patients.